The present invention relates to a powder feeder in an apparatus for feeding a powder by means of an air or a gas.
When a powder ore containing, e.g., a metal oxide, is pre-reduced and is then reduced at molten state to manufacture a molten metal, a powder feeder for feeding powder ore by an air or a gas is required in a powder ore feeder from a pre-reduction furnace to a smelting reduction furnace, a dust delivery unit of an exhaust gas combustor in a rotary kiln process for reduced iron production, or a sand recovery feeder in a molding sand roasting furnace.
However, a powder feeder used in such a location, particular, a feeder arranged on a powder ore feeder, cannot be a mechanical powder feeder, e.g., a rotary feeder since an object to be fed is at high temperatures around 1,000.degree. C. Therefore, demand has arisen for a feeder capable of feeding a high-temperature powder.